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G.E. Groschen

Publications and source records attributed to G.E. Groschen.

5 recordsLinked to original sources
USGS2011

Diel cycles in dissolved barium, lead, iron, vanadium, and nitrite in a stream draining a former zinc smelter site near Hegeler, Illinois

Diel variations in the concentrations of a number of constituents have the potential to substantially affect the appropriate sampling regimen in acidic streams. Samples taken once during the course of the day cannot adequately reflect diel variations in water quality and may result in an inaccurate understanding of biogeochemical processes, ecological conditions, and of the threat posed by the water to human health and the associated wildlife. Surface water and groundwater affected by acid drainage were sampled every 60 to 90 min over a 48-hour period at a former zinc smelter known as the Hegeler Zinc Superfund Site, near Hegeler, Illinois. Diel variations related to water quality in the aquifer were not observed in groundwater. Diel variations were observed in the temperature, pH, and concentration of dissolved oxygen, nitrite, barium, iron, lead, vanadium, and possibly uranium in surface water. Temperature, dissolved oxygen, nitrite, barium, lead, and uranium generally attained maximum values during the afternoon and minimum values during the night. Iron, vanadium, and pH generally attained minimum values during the afternoon and maximum values during the night. Concentrations of dissolved oxygen were affected by the intensity of photosynthetic activity and respiration, which are dependent upon insolation. Nitrite, an intermediary in many nitrogen reactions, may have been formed by the oxidation of ammonium by dissolved oxygen and converted to other nitrogen species as part of the decomposition of organic matter. The timing of the pH cycles was distinctly different from the cycles found in Midwestern alkaline streams and likely was the result of the photoreduction of Fe 3+ to Fe 2+ and variations in the intensity of precipitation of hydrous ferric oxide minerals. Diel cycles of iron and vanadium also were primarily the result of variations in the intensity of precipitation of hydrous ferric oxide minerals. The diel variation in the concentrations of lead, uranium, and barium may have been affected by competition with Fe + 2 for sorption sites on hydrous ferric oxide minerals.

Illinois↗
USGS2002

Determination of nanogram per liter concentrations of volatile organic compounds in water by capillary gas chromatography and selected ion monitoring mass spectrometry and its use to define groundwater flow directions in Edwards Aquifer, Texas

A method has been developed to measure nanogram per liter amounts of selected volatile organic compounds (VOCs) including dichlorodifluoromethane, trichlorofluoromethane, cis-1,2-dichloroethene, trichloroethene, tetrachloroethene, and the isomers of dichlorobenzene in water. The method uses purge-and-trap techniques on a 100 mL sample, gas chromatography with a megabore capillary column, and electron impact, selected ion monitoring mass spectrometry. Minimum detection levels for these compounds ranged from 1 to 4 ng/L in water. Recoveries from organic-free distilled water and natural groundwater ranged from 70.5% for dichlorodifluoromethane to 107.8% for 1,4-dichlorobenzene. Precision was generally best for cis-1,2-dichloroethene, tetrachloroethene, and the dichlorobenzene isomers and worst for dichlorodifluoromethane and trichlorofluoromethane. Blank data indicated persistent, trace-level introduction of dichlorodifluoromethane, 1,4-dichlorobenzene, and tetrachloroemene to samples during storage and shipment at concentrations less than the method reporting limits. The largest concentrations of the selected VOCs in 27 water samples from the Edwards aquifer near San Antonio, TX, were from confined-zone wells near an abandoned landfill. The results defined a zone of water with no detectable VOCs in nearly all of the aquifer west of San Antonio and from part of the confined zone beneath San Antonio.

Analytical Chemistry↗
USGS1994

Analysis of data from test-well sites along the downdip limit of freshwater in the Edwards Aquifer, San Antonio, Texas, 1985-87

Many researchers have studied the downdip limit of freshwater in the Edwards aquifer or various aspects of the saline-water zone and its relation to the freshwater zone. These studies were summarized and used to synthesize a consistent hydrologic and geochemical framework from which to interpret data from field studies. The concept derived from the previous work on the downdip limit of the freshwater zone is that fresh recharge water entered the aquifer and developed a vast flow system controlled by barrier faults. Some recharge water flows into the saline-water zone rather than toward major freshwater discharge points. The water that enters the salinewater zone continues to dissolve gypsum and dolomite, and calcite precipitates out of the water. This process of dedolomitization has helped to develop the large secondary porosity of the freshwater zone as the downdip limit of the freshwater zone progressively moved downdip in recent geologic time. The drilling of test holes and installation of monitoring wells began in 1985 and helped to define the downdip limit of the freshwater zone at one location. Dolomite was found in greater amounts in rocks from the saline-water-zone test hole than in rocks from the freshwater-zone test hole. Other mineralogic and lithologic contrasts between the saline-water-zone test hole and the freshwater-zone test hole support the conceptual model of dedolomitization. Geophysical logs and test-hole survey logs helped to define the stratification of freshwater and associated altered rock textures, secondary porosity development, and water chemistry in the freshwater-, saline-water-, and transition-zone test holes. The differences in actual measured head among the seven completed monitor wells varied over time, especially during periods of substantial water use. The water levels in two monitor wells completed at the freshwater zone (site D; wells Dl and D2) responded quickly and strongly to withdrawals. In the transition zone (site C; wells Cl and C2), the water level in the shallow monitor well (Cl) completed in a cavern responded quickly, but because it was farther from the water-supply wells near site D, it did not respond as strongly to changes in withdrawals at the nearby well field. The water levels in the three salinewater wells at site A (Al, A2, and A3) and the deep site C well (C2) were less responsive to stresses relative to the water-level changes in the freshwater wells (Dl, D2, and Cl). Large amounts of freshwater were produced from the upper 300 to 350 feet of the aquifer in the freshwater zone (site D). Water produced from below this interval was as saline as that from the saline-water zone (site A). The cavern near the top of the aquifer in the transition zone (site C) produced large amounts of freshwater. The freshwater produced from the cavern was of a different geochemical type than the water from the other wells. The saline-water-zone test hole (site A) produced small amounts of water having specific conductance generally about 5,800 to 6,200 microsiemens per centimeter at 25 degrees Celsius. A consistent trend in the water quality was not detected in the monitor-well data for July 1986-April 1987. This was caused, in part, by the average to above-average rainfall and by the lack of large withdrawals during the period. The water quality of samples from several of the wells was similar to the water quality determined by a previous study of the area. Geochemistry of the oil- or gas-well brines from downdip in the saline-water zone had slight resemblance to the geochemistry of the water at the downdip limit of freshwater; updip flow of saline water toward the freshwater zone was not indicated.

Texas↗
USGS1981

Limnological and geochemical survey of Williams Lake, Hubbard County, Minnesota

A limnological and geochemical survey of Williams Lake, Minnesota, was made in 1979 to provide an initial interpretive description of the lake and the contiguous ground-water system. This survey was made as part of a continuing research program related to the investigation of the interaction of lakes and their contiguous ground-water systems at Williams Lake, Minnesota, as well as other sites within the continental United States. During 1979, Williams Lake was dimictic, and the lake had high optical transparency; light penetrated to the lakebed throughout most of the lake. Aquatic macrophytes were present along the western shore and in the southern bay of the lake. Although the lake had clinograde-oxygen distributions during part of this survey, anaerobic conditions were not observed. The lake is moderately fertile with respect to its total phosphorus content. Nutrient data indicate phosphorus limits phytoplankton biomass levels in Williams Lake. Blue-green algae were the dominant group of the phytoplankton community and copepods were the dominant group of the zooplankton community when the lake was thermally stratified during the open-water season. Diatoms and rotifers were dominant when the lake was isothermal in the autumn. Calcium and bicarbonate represent more than 90 percent of the dissolved constituents in Williams Lake and the contiguous ground-water system. Major mineralogical constituents of the lake sediments are quartz, dolomite, and calcite. Marl is present only in the littoral zone of the lake. Organic sediments in the lake consist of loose organic floe and gyttja.

Minnesota↗